/QUEEN - Tám hậu

              //#include <windows.h>

        #include <iostream>
        using namespace std;
        #define N 8
        int y;
        int x;
        
        // ham kiem tra viec dat hau tai vi tris (x,y) co ok khong
        bool isSafe(int board[][N], int row, int col) {
          // neu phia ben trai hang hien tai da co quan hau
          for (int i = 0; i < N; i++) {
            if (board[row][i] == 1) {
              return false;
            }
          }
        
          // kiem tra duong cheo tren (trai)
          for (int i = row, j = col; i >= 0 && j >= 0; i--, j--) {
            if (board[i][j] == 1) {
              return false;
            }
          }
        
          // kiem tra duong cheo tren (phai)
          for (int i = row, j = col; i >= 0 && j < N; i--, j++) {
            if (board[i][j] == 1) {
              return false;
            }
          }
        
          // kiem tra duong cheo duoi (trai)
          for (int i = row, j = col; i < N && j >= 0; i++, j--) {
            if (board[i][j] == 1) {
              return false;
            }
          }
        
          // kiem tra duong cheo duoi (phai)
          for (int i = row, j = col; i < N && j < N; i++, j++) {
            if (board[i][j] == 1) {
              return false;
            }
          }
        
        
          // ok
          return true;
        }
        
        bool solQueen(int board[][N], int col) {
          void showResult(int board[][N]);
        
          /*cout << "==========\n";
          showResult(board);
          Sleep(1000);*/
        
          /*if (col < 0) {
            return false;
          }*/
        
          if (col >= N) {
            return true;
          }
        
          if (col == x - 1) solQueen(board, col + 1);
          else {
            // xet tung cot tren ban co lan luot dat hau o cac hang phu hop
            for (int i = 0; i < N; i++) {
              if (isSafe(board, i, col)) {
                board[i][col] = 1; // dat hau o vi tri (i, col)
                if (solQueen(board, col + 1)) { // dat hau o cot tiep theo dan toi 1 loi giai
        
                  return true; // thong bao co loi giai
                }
                else {
                  board[i][col] = 0;
                }
              }
            }
            //if (col - 1 == x - 1) solQueen(board, col - 2);
            return false;
          }
        }
        
        void showResult(int board[][N]) {
          for (int i = 0; i < N; i++) {
            for (int j = 0; j < N; j++) {
              if (board[i][j] == 1) {
                cout << "w";
              }
              else {
                cout << ".";
              }
            }
            cout << endl;
          }
        }
        
        int main() {
          cin >> y;
          cin >> x;
        
          int board[N][N] = { 0 };
          board[y - 1][x - 1] = 1;
          bool result = solQueen(board, 0);
          if (result) {
            showResult(board);
          }
          else {
            cout << "Loi\n";
          }
          return 0;
        }